Re: Subtracting G channel from R and B may increase lossless compression?

Anybody knows if this conversion is Patent protected? I really want to be aware from patent stuff.

Thank you.

"LiloLilo" <danilo.brambilla@xxxxxxxx> wrote in message news:4655e5ba$0$16029$5fc30a8@xxxxxxxxxxxxxxxxxx
Thank you very much. Very userfull link.

It seems that this kind of transformation would be quite different from the usual YUV. Do you think that this difference would be small? Is there any comparison between them?

Suppose I have now converted my color space from RGB to YUV and let's speak again of channel differencing. The correct differencing now wold be U-Y, V-Y and Y?

Thank you all for help, you are great!

"CBS" <cbs.strutz@xxxxxx> wrote in message news:46549C91.8090100@xxxxxxxxx
see

http://www.jpeg.org/.demo/FAQJpeg2k/functionalities.htm#What%20is%20the%20RCT?

for lossless colour transform

Regards,
CBS


LiloLilo wrote:
I was looking for lossless conversion from RGB to YUV but I found out
that this kind of conversion isn't possible in a lossless way because of
several RGB colors represent the same YUV color
(http://www.doom9.org/index.html?/capture/digital_video_color.html).
Please could you provide more information about this point?

Thank you very much.

Danilo


"Jim Leonard" <MobyGamer@xxxxxxxxx> wrote in message
news:1179930643.817061.276640@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
On May 22, 3:58 pm, "LiloLilo" <danilo.brambi...@xxxxxxxx> wrote:
anybody knows how subtracting G channel from R and from B could
increase
lossless compression? I did some tests on some images and found out that
this is true but not for all images. Images with more noise compress
worst.
Do you think that subtracting for example the R channel or the B channel
instead of G would be different?

It depends on the source material. Better correlation is always found
if you convert the RGB image into a YUV image (the transform is
reversable; losslessly if you have enough precision).




.

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